I can't seem to find this. I have an app that checks a web page every minute, saves a copy when it changes and faxes it somewhere. Sometimes it goes a whole day without doing anything so it's a waste to have the hard drives spinning. How can I turn the drives off after so many minutes of inactivity and have them spin up when my script tries to save to it?

spindown
Set or report timeout after which the device will be spun down. To arm the timeout the device needs at least one more request after setting the timeout. To disable spindown, set the timeout to zero. No further actions are needed in this case.